The objective of the proposed research is to evaluate simple experimental techniques for studying broadband ultrasonic pulse propagation. Preliminary studies have demonstrated that optical diffraction principles can be used to develop simple experimental systems from readily available components. The proposed validation of these systems would help to encourage the acquisition and comparison of fundamental data required for an improved understanding of ultrasound-tissue interactions. Systematic procedures will be developed for studying pulses transmitted by unfocussed circular piston medical ultrasound transducers into distilled water. Results obtained from several optical methods will be compared over a wide range of experimental conditions. Comparisons will be made with results obtained from other measurement techniques. The ultrasound frequency range, bandwidth limits and power range over which the optical methods can be accurately applied will be determined. The effects of different transducer geometries, focussing arrangements and excitation conditions on the optical signals will be studied. Required corrections or limitations of the methods will be determined. Several acoustical properties of excised tissue samples and biologically relevant media will be studied with the optical methods. Comparisons will be made between these results and those obtained using conventional measurement methods. Broadband pulse propagation in a non-linear, attenuating medium will be studied with the non-perturbing optical methods to help formulate models for pulse propagation in tissue. The practical use of simple optical diffraction systems in a clinical environment will be investigated. The output characteristics of commercial medical diagnostic systems will be documented and compared with results from other studies.